Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

inkyvoyd

  • 2 years ago

Related rates (parametric derivatives)

  • This Question is Closed
  1. inkyvoyd
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    if y=3x^2+2x and dx/dt=4, find dy/dt when x=3 My answer: dy/dt=24x+8; dy/dt=80. Can someone please check this? THanks!

  2. tamtoan
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    isn't it dy/dt = 6x dx/dt + 2dx/dt ? can someone check this ?

  3. inkyvoyd
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    :S

  4. zepdrix
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Yah @tamtoan is on the right track there,\[\huge y=3x^2+2x\]If we take the derivative with respect to TIME, we'll get,\[\huge \color{#CC0033}{\frac{dy}{dt}}=6x\color{#F35633}{\frac{dx}{dt}}+2\color{#F35633}{\frac{dx}{dt}}\]And they gave us information about dx/dt and x.\[\huge \color{#CC0033}{\frac{dy}{dt}}=6(3)(\color{#F35633}{4})+2(\color{#F35633}{4})\]Understand where those numbers are coming from?

  5. inkyvoyd
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Uh, the answer is defienitely 80, because I just submitted te assignment. Let me go over what happened though

  6. inkyvoyd
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yeah, @zepdrix , you have the dx/dt because x is a function of t; @tamtoan didn't have that. Thanks.

  7. zepdrix
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Tam had the same thing, he just didn't plug in the x and dx/dt values for you :D

  8. inkyvoyd
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Oh he did :S. Well, thanks for helping out!

  9. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.